Answer: 18.5% of the bill.
Explanation:
Since the bill was 42 dollars while the total amount was 49.77, we need to subtract 42 by 49.77.
49.77 - 42 = 7.77.
So the tip was $7.77.
But then we also have to find the tip as a percentage.
So we should do 7.77 divided by 42, because 42 is the original amount.
7.77 ÷ 42 = 0.185, but as a percent you have to move to the left two places. So the decimal is 18.5.
In conclusion, the tip was 18.5% of the bill.
Hope this helps!